Traditionally, there has been known, as an automobile periphery information display system, a navigation device 2 that displays map information to guide a driver to a destination as being mounted on a vehicle such as an automobile. The navigation device 2 has map information stored in a map database, specifies a current position of the vehicle using GPS information received from a GPS satellite, and reads and displays map to the destination from moment to moment in accordance with travelling of the own vehicle.
Here, the map information is information mainly consisting of roads. When many regions where information amounts are extremely small exist in a screen, the screen becomes inefficient. In view of the above, there has been known a navigation device that superimposes and displays additional information on the display screen of the map in addition to the road information (e.g., see Patent Literature 1 and Patent Literature 2).